In the case you site.......
You have just explained why we have a court system. And that would be your proper recourse. In my state you are not fighting the deep pockets of government, government will foot your legal bills.
No foul, if you believe in a system of laws. This is part of the checks and balances system we vaunt, remember?
On the other hand, perhaps you feel Wal-Mart can not only effectively bribe the zoning board, the zoning appeals board, but the county or city commissioners, AND the courts as well?
Wow, I am glad I don't have to live in your neighborhood. Come to Florida, the weather is fine, the sun shines, and even Wal-Mart couldn't get away with what you fear here.
Publius